v SPECIES OF ECHIDNA 111
In the skull the Echidna differs from OrnitJiorliynclius in
the greater extension backwards of the palatines, and the larger
size of the pterygoids. The extent and relations of these bones
to each other is not at all unlike that which obtains in many
Whales. The premaxillae show traces of the same divergence
followed by convergence- of their ends that is seen in the
Platypus. There are only sixteen pairs of ribs, and either
three or four lumbar vertebrae, JSchidna has no trace of teeth,
and there are no horny pads which take their place; the mouth
is as edentulous as in the true American Anteaters. The brain
(Fig. 53) is marked by sulci, contrary to what we find in
OrnithorhyncJius. The genus has been divided into three species,
FIG. 54.—Australian Anteater. Echidna acuieata.
but it is doubtful whether more than one can be allowed, which
ranges from Australia through the Papuan region. "While there
is but one species of true Scliidna, a New Guinea species must
clearly be referred to a distinct genus Proechidna* This animal
is to be distinguished by the fact that there are usually but
three toes on each foot. But there are copious rudiments of
the other phalanges, upon which claws are sometimes developed.
The beak is curved downwards, and. the back is rather arched ;
the whole animal has the most singular likeness to an Elephunt !
The ribs are increased by one pair, and there are four lumbar
vertebrae. The one species is named JP. 'bruijnii. The Hon. "W,
Bothschild 2 distinguishes a form JR. nigroaculeata, which is allowed
by Mr. Lydekker.
1 Zaglossus lias apparently priority as a name ; but Proeclvid<a& is better known.
2 Proc. Zool. Soc. 1892, p. 545.